The present invention relates to a heater mechanism, especially for vehicles, such as vans, buses, trailers, mobile homes, and boats, and for so-called weekend houses. The mechanism includes a closed combustion chamber that is heated by open flames of a combustion gas generated from solid, liquid, or gaseous fuel. Heat is transferred from the combustion chamber to a heat-carrier that is disposed in a heating chamber that surrounds the combustion chamber. For indirect or direct transfer of heat to a room that is to be heated, the heat carrier is conveyed via at least one flowproducing mechanism, which is driven by an electric motor that is supplied with power that is obtained via at least one thermoelectric generator from the heat generated by the flame in the combustion chamber.
Heater mechanisms of the aforementioned general type are known from German Patent No. 3 148 162. These heater mechanisms have the advantage of not having to be dependent upon an additional power source, such as a battery, in order to drive the electric motor of the flow-producing mechanism during operation of the heater mechanism. If the heater mechanism is designed to heat air in the heating chamber from the combustion chamber, and to convey this hot air directly into the room that is to be heated, the flow-producing mechanism is a fan or similar blower. On the other hand, if the heater mechanism is designed for a heat carrier, preferably water, that is circulated in a closed system, and the heat of which is transferred to the air of a room via a heat exchanger that is disposed in the room, the flow-producing mechanism is a pump that circulates the liquid heat carrier between the heating chamber and the heat exchangers. In this case, heat is transferred indirectly from the combustion chamber to the room that is to be heated up.
Independently of the configuration of the heater mechanism and the type of heat carrier, it has been discovered that the thermoelectric generators, which operate pursuant to the Seebeck effect, generate very little electrical power, so that a large number of such generators are needed in order to produce the power required for driving the flow-producing mechanism. During the course of further development of semiconductor technology, thermoelectric generators in the form of platelike semiconductor elements have been produced that have a considerably greater efficiency. However, the drawback of these plate-like semiconductor elements is that their maximum operating temperature is considerably less than that of the heretofore known thermoelectric generators.
It is therefore an object of the present invention to improve a heater mechanism of the aforementioned general type in such a way that it is suitable for use with plate-like semiconductor elements as thermoelectric generators while at the same time protecting the semiconductor elements from overheating, and also improving cooling of the cold side.